Junction circulator wherein each center conductor leg appears on both sides of the insulation board



4, 1970 TADASHI HASHIMOTO ET AL 3, ,5

JUNCTION CIRCULATOR WHEREIN EACH CENTER CONDUCTOR LEG APPEARS ON BOTH SIDES OF THE INSULATION BOARD Filed May 6, 1968 2 SheetS-Sheet 1 (PRIOR ART) (PRIOR ART) mm m m m m H w R wlm 03 AAAA TTTM g- I970 TADASHI HASHIMOTO ET AL 5 5 JUNCTION CIRCULATOR WHEREIN EACH CENTER CONDUCTOR LEG APPEARS ON BOTH SIDES OF THE INSULATION BOARD Filed May 6 1968 2 Sheets-Sheet 2 Hg. 5%! F791 55 INVENTORS TAOASHI HASHIMOTO TARO MIU'RA TAKASH/ IWATA MAsANom SASAKI U.S. Cl. 3331.1 Claims ABSTRACT OF THE DISCLOSURE A c rculator wherein at least three conductor elements insulated from one another are radially arranged at an equal angle with one another, the insulation of each element from another element being arranged in such manner that a substantial part of the leg of at least one element is formed on one surface of an insulating plate, the remaining part of the leg where intersecting the leg of the other element being formed on the other surface of said insulating plate, said substantial part and the remaining part of the leg being skip-connected through holes in said plate with a conductive material.

This invention relates to a printed circulator which is stable in the operation and can be made at a low cost.

To reduce the size and weight, various types of lumped parameter circulators have been suggested and many of them have been practically used. Their construction is substantially as shown in FIG. 1. In the drawing, 1 is such magnetic material for high frequencies as ferrite,

2 is a central conductor, 3 is a shielding case, 4 is a,

condenser, 5 is a magnet for providing a magnetic field to the magnetic material 1 for high frequencies, 6 is a connector for an input or output, and 7 is a housing. The central conductor 2 is, as shown in FIG. 2, of a construction wherein three element conductors A, B and C electrically insulated from one another are knitted in the form of meshes. In each construction, there are certain limits to the insulation of the central conductor and to the precision in the case of knitting the element conductors together in the form of meshes. The nonuniformity of this knitted geometrical arrangement has been a cause of deteriorating the characteristics of a circulator. Further, as shown in FIG. 1, the condenser 4 is connected in order to form a circulator. However, when the frequency band is of VHF of more than 30 to 300 megacycles, the length of the lead Wire for connecting the condenser and the arrangement of the condensers will influence the characteristics of the circulator. Therefore, if the connection is nonuniform, it will be a cause of deteriorating the characteristics. In order to control the deterioration of the characteristics due to such causes as are mentioned above, the capacity value of the condenser has been varied in various manners. But, due to the time required for the control, the cost has become rather high.

An object of the present invention is to provide a circulator which is low in the fluctuation of characteristics and can be made at a low cost.

Other oibjects and advantages of the present invention will become clear upon reading the following detailed explanation with reference to the drawings, in which:

FIG. 1 is a sectioned view of a conventional circulator.

FIG. 2 is an arrangement view of a conventional central conductor.

FIG. 3 is an arrangement view of a central conductor of the present invention.

FIGS. 4A and 4B are arrangement views of symmetri- States Patent 0 ice cal central conductors according to the present invention.

FIGS. 5A and 5B are arrangement views of condensers.

FIGS. 6A and 6B show other embodiments of the present invention.

FIG. 7 is a sectioned view of a circulator of the present invention.

While the invention has been described in connection with the preferred embodiments, it will be understood that we do not intend to be limited to the particular embodiments shown but intend, on the contrary, to cover the various alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.

Generally, the meshed parts of the central conductor require the overlapping of the element conductors and, therefore cannot be formed in the same plane. But, if the two front and back surfaces of an insulating plate are utilized, the three circuits (conductors) insulated from one another can be formed in a plane surface, while intersecting with each other. That is to say, by arranging only the parts of the conductor legs intersecting of overlapping the other conductor legs on the second (back) surface of the insulating plate, susbtantial part of all the conductors may be arranged on the first (front) surface of the insulating plate. An example of the thus formed central conductor is shown in FIG. 3. A, B and C, respective elements having substantially U-shaped legs and forming a circulator, are insulated from one another and are radially arranged at an equal angle with one another. In the drawing, the part shown with the broken lines represents the element or parts thereof arranged on the second surface (back surface). Further, the parts shown with the round mark are points electrically connecting both front and back surfaces. The element A is arranged on the first surface (front surface) of an insulating plate (not illustrated) and the element B is arranged on the second surface (back surface). The parts shown with the broken lines in the element C, where intersecting the element A, are arranged on the second surface (back surface). The parts arranged on the first and second surfaces, respectively, in the element C are connected with a conductive material, by way of so-called skip-connection across through holes made in the insulating plate. In the example shown in FIG. 3, however, the three element conductors are not uniformly distributed on the front and back surfaces and, therefore, are not electrically prefectly symmetrical. In case the conductor is used as an isolator with a matched load connected to one terminal, it will be sufficient. However, where a swmmetrical three-terminal circulator is required, such pattern as is shown in FIGS. 4A and 4B may be preferable. In the FIGS. 4A and 4B, A, B and C are respective elements forming a circulator. In the FIGS. 4A and 4B, the solid lines show a pattern on the front surface and the broken lines show a pattern on the back surface. The round mark represents a point electrically connecting the front and back surfaces. In FIG. 4A, in the U-shaped element A, the part shown with the solid lines in the leg part in arranged on the first surface (front surface) of the insulating plate, the part shown with the broken lines is arranged on the second surface (back surface) and the parts arranged on the first and second surfaces, respectively, are connected with such conductive material as a pin passing through the first and second surfaces to form a skip-connection across the through holes. The elements B and C are formed similar to the element A. The parts in each of the legs in which the elements A and B, B and C and C and A are respectively overlapped, are skip-connected through the holes, so that the legs may be electrically insulated from legs of the other element. In FIG. 4A, all the overlapped parts are skip-connected through the-holes and the terminals of the three conductors arein the same plane, but there are too many points connecting the front and 3 back surfaces. It is advantageous to reduce such connecting points so as to make the manufacture easier, and thus an example in which such connecting points are reduced is shown in FIG. 4B. In such case, the front and back connecting points in the skip-connecting parts will be half as many as in the case of FIG. 4A. The free ends of the legs of the respective elements are arranged as divided on the first and second surfaces.

In the above, embodiments of print-wiring central conductors and their effects have been referred to in detail. As described above, even in the connection of condensers, there have been problems and time has been required for the adjustment. According to the present invention, the condensers can be made on the same board as of the central conductor and, therefore, the difficulties accompanying the connection of the condensers can be also solved. In practice, two different techniques have been advanced for connecting condensers in a circulator, as shown in FIGS, 5A and 5B. Preferred formations of printed circuits, each corresponding to the above connecting method, are shown in FIGS. 6A and 6B. In these figures, 8 is an element, 9 is a terminal and 10 is one of electrodes forming a condenser, the other electrode (not illustrated) being provided on the surface opposite it. 11 is a connecting line connecting the element 8 and electrode 10. 12 is a fixed part of a shielding case (not illustrated). In this embodiment, the element is grounded together with the shielding case. Parts in broken line represent parts of elements formed on the back surface. The element in this case is not U-shaped, but is formed of legs closed at the ends corresponding to the free ends of above mentioned U-shaped elements, so as to be substantially rectangular. FIGS. 6A and 6B correspond, respectively, to FIGS. 5A and 5B.

FIG. 7 is a sectioned view of a circulator of the present invention. In the drawing, 1 is a magnetic material for high frequencies formed in a disk shape, which is arranged on upper and lower surfaces of a double surface printed board 2 and enclosed in a shielding case 3. 5 is a permanent magnet of a disk form, which is arranged so as to oppose said magnetic material 1 for high frequencies, and mounted on inside surface of a housing 7 consisting of a magnetic material. 6 is a connector, three of which are provided on the side wall of said housing 13 is a grounding plate, which is utilized for holding said double surface printed board 2 while acting as a grounding means. While there are provided three connectors 6 in this particular circulator, only two of them are illustrated in the FIG. 7, which shows a sectional view taken along said two connectors.

According to the present invention, as described above, a three-terminal circulator inner component is provided for use in a circulator having a magnetic material set for high frequencies and a shielding case, which inner component can be made much more simply than by any conventional method, and thus a circulator having uni form characteristics can be provided.

What is claimed is:

1. An electronic circulator comprising a ground plate, ferromagnetic disc means having a selectively variable permeability, magnetic means creating a DC magnetic field transverse to said disc means, an insulating plate disposed adjacent and parallel to said disc means, and at least three conducting elements radially arranged to cross said insulating plate and intersect at equal angles to one another with their common intersection point aligned axially with said disc means, each of said conducting elements having a pair of legs with portions thereof selectively formed on opposite sides of said insulating plate with connections through said plate to electrically connect said portions on opposite sides, thereby allowing the legs of said conducting element to intersect the legs of the other elements on opposite sides of said plate to maintain electrical isolation therebetween.

2. An electronic circulator according to claim 1 wherein the major portion of each conducting element is formed on a single side of said insulating plate and wherein only selected portions of said member intersecting other members are formed on the other side of said plate.

3. An electronic circulator according to claim 1 wherein the insulating plate is a printed circuit board and the conducting elements are selectively printed on opposite sides of said board.

4. An electronic circulator according to claim 1 wherein said elements are interconnected through condensers, the plates of which are formed on opposite sides of said insulating plate.

5. In an electronic junction circulator of the type comprising a ground plate and a ferromagnetic disc adapted to be biased by a transverse DC magnetic field, the improvement comprising an insulating plate, and at least three conducting elements radially arranged to cross said insulating plate and intersect at equal angles to one another, each of said conducting elements having a pair of legs with portions thereof selectively formed on op posite sides of said insulating plate with connections through said plate to electrically connect said portions on opposite sides, thereby allowing the legs of said conducting elements to intersect the legs of the other elements on opposite sides of said plate to maintain electrical isolation therebetween.

References Cited UNITED STATES PATENTS 3,334,318 8/1967 Nakahara et a1. 333-1.1 3,335,374 8/1967 Konishi 3331.1

HERMAN KARL SAALBACH, Primary Examiner P. L. GENSLER, Assistant Examiner US. Cl. X.R. 33384 

